The present invention relates to a decorative lamp assembly and more particularly, to such a decorative lamp assembly, which causes colored tiny plastic balls to move up and down with bubbles in an enclosed ornamental tube when turned on to emit light.
FIGS. 1˜3 show a decorative lamp assembly 9 according to the prior art. This structure of decorative lamp assembly 9 is comprised of an adapter 91, a bulb 911, a lampshade 92, and an ornamental tube 93. The adapter 91 has a socket side adapted to receive the bulb 911, and a plug side adapted to receive power supply from an electric outlet. The lampshade 92 is comprised of an upper shell 921 and a bottom shell 922. The ornamental tube 93 is an enclosed tube of glass material, having a porous bottom stuffing layer 931 formed of sodium silicate (NaSiO2) and silica (SiO2), and an upper stuffing material of dichloromethane (Ch2Cl2) 90. During fabrication of the ornamental tube 93, sodium silicate (NaSiO2) and silica (SiO2) are put in the tube and heated to about 30°˜35° C. When cooled down, sodium silicate is condensed and bonded to the inside wall of the tube. After formation of the porous bottom stuffing layer 931, dichloromethane 90 is put in the tube with a space left above dichloromethane 90, and then the tube is sealed after exhaust of inside air. The lampshade 92 is fastened to the adapter 91 around the bulb 911. The ornamental tube 93 is fastened to the top side of the upper shell 921 of the lampshade 92, keeping the bottom end suspended above the bulb 911. When turned on the bulb 911, heat energy is transmitted from the bulb 911 through the porous bottom stuffing layer 931 to the upper stuffing material of dichloromethane 90 to boil dichloromethane 92 into bubbles 900. At the same time, light rays pass from the bulb 911 through the porous bottom stuffing layer 931 and the bubbles 900, producing a lighting effect.
The ornamental tube 93 of the aforesaid decorative lamp assembly has drawbacks as follows:    1. Because the ornamental tube is made of glass, it tends to break, and the broken chips of the glass material may injure a person accidentally.    2. It takes much time to have heat energy be transmitted from the bulb 911 through the porous bottom stuffing layer 931 to the upper stuffing material of dichloromethane 90 to boil dichloromethane 92 into bubbles 900.    3. It is difficult to control the quality of the porous bottom stuffing layer 931 by using sodium silicate (NaSiO2) and silica (SiO2) to make the porous bottom stuffing layer 931. If the pores of the porous bottom stuffing layer 931 are not well controlled, convection of bubbles become unstable.
Therefore, it is desirable to provide an ornamental tube for decorative lamp assembly that eliminates the aforesaid drawbacks.
The present invention has been accomplished under the circumstances in view. It is therefore one object of the present invention to provide an ornamental tube for use in a decorative lamp assembly to produce a convection of bubbles, which is safe in use. It is another object of the present invention to provide an ornamental tube for use in a decorative lamp assembly to produce a convection of bubbles, which greatly shortens the heating time to heat the filled organic solvent to the boiling status. It is still another object of the present invention to provide an ornamental tube for use in a decorative lamp assembly, which produces a stable convection of bubbles quickly after the lamp bulb has been turned on. To achieve these and other objects of the present invention, the ornamental tube fastened to the lampshade of a lamp and holding an organic solvent for heating into a boiling status by heat energy from a lamp bulb in the lampshade to produce a convection of bubbles below an inside space thereof, the ornamental tube comprising a plastic tube body holding the organic solvent and defining the space above the organic solvent, the plastic tube body admitting light and having an open bottom side, a plastic bottom cap capped on the open bottom side of the plastic tube body, the plastic bottom cap admitting light, a spacer member mounted inside the plastic bottom cap and sealed to the bottom open side of the tube body, the plastic bottom cap having a plurality of through holes through top and bottom sides thereof for guiding the organic solvent from the tube body to the inside of the plastic bottom cap for heating by heat from the lamp bulb, and a porous cushion mounted in between the plastic bottom cap and the spacer member and adapted to absorb the organic solvent for heating by heat energy from the lamp bulb.